Oil well mast gin pole



Feb., 5, 1957 l H. J. WOOLSLAYER Erm. 29,780,325

OIL WELL MAST GIN POLE Filed Nov@ 27, 1955 05 1 f l Y[i l Q N bww N r uen f n Il n N A fn m i i u N m,

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Mo@ Qu@ ya Mm United States Patent O on. WELL MAST GIN Pour Homer J.Woolslayer, Charles D. Iddings, Paul E. Borg, and Cecil Jenkins, Tulsa,Okla., assignors to Lee C. Moore Corporation, Pittsburgh, Pa., acorporation of Pennsylvania Application November 27, 1953, Serial No.394,698 6 Claims. (Cl. 18916) This invention relates to upwardly taperedgin poles that areused in raising and lowering portable oil well masts,and more particularly to those that remain in position as a part of orclose to the upright mast.

The gin pole with which this invention is concerned is the type that haslaterally spaced front legs and laterally spaced rear legs, with theupper ends of the front legs connected to the rear legs but with theirlower ends spaced wide apart. Such a gin pole therefore has inclinedfront and back sides, or one side inclined and the other side vertical.It supports cables that are used in swinging a reclining mast up toupright position. ln most cases the gin pole then becomes a part of theupright mast and helps to support it, although in some instances themast stands on its own four feet and is` not connected to the gin pole.Because the front legs of the gin pole are under compression while amast is being raised, it is customary to connect their upper portionswith a truss. After the mast has been raised and put in operation, thistruss is likely to be in the line of vision ofthetdrawworks operator,who must watch the traveling block moving up and down in the mast. Also,in the more general case where the gin pole forms a part of the erectedmast, the trussed front side of the gin pole serves no particularfunction after the mast is upright, but the untrussed rear side of thegin pole is under compression so that the rear legs have to be madeheavy enough to take the load.

It is among the objects of this invention to provide a gin pole inwhichthe back legs need not be madeas strong and heavy as heretofore, inwhich the truss that normally connects the front legs of the gin polecan be used for` bracing the rear legs after the mast is raised, andwhich provides for an improved tield of vision for the draw worksoperator. p

vIn accordance with this invention the truss in the upper part of thegin pole has a top longitudinal member which is pivotally supported on ahorizontal axis so that the truss can be swung from a position betweenthe front legs to a position between the rear legs. Means are providedfor detachably connecting the bottom of the truss to the front legs, andmeans also are provided on the rear legs for connection to the bottom ofthe truss when itis swung back to them. Preferably, 4the toplongitudinal member of the truss connects the legs at the opposite sidesof the gin pole and is rotatable on its own axis. In its front positionthe truss serves its customary purpose, but in its rear position itreinforces the rear legs of the gin pole and also leaves the spacebetween the upper portions of the front legs unobstructed so that thedrawworks operator can see up into the mast better,

The preferred embodiment of the invention is illustrated in theaccompanying drawings, in which Fig. 1 is an enlarged side view of theupper part of the gin pole, with parts broken away;

Fig. 2 is a rear view of the upper part of the gin pole, with one of theback legs broken away; and

Fig. 3 shows diagrammatically how such a gin pole may be used forraising a mast.

ICC

Referring to the drawings, the gin pole has a pairof laterally spacedfront legs 1 and a pair of laterally spaced` rear legs 2. The legs arebuilt up from structural steel members and taper downward from widetops. The upper ends of the rear legs are provided with forwardlyextending vertical plates 3, each of which is straddled by a fork v 4 onthe upper end of a front leg. The forks and platesy are provided withaligned holes, in which pivot pins 5 are mounted so that the front andthe rear legs can be swung toward each other to fold the gin pole whenit is not in use. When the gin pole is in operating position, eachconnected pair of legs diverge downward as shown in Figs. l and 3 andhave their lower ends mounted in' any suitable manner on a support 6.Rigidly mounted at the top of each rear leg is a horizontal sleeve 7.The two sleeves are disposed with their axes in alignment. An anchorbracket 8 may be rotatably mounted on the center of each sleeve betweencollars 9 for attachment to the ends of a sling line 11 (Fig. 3) used inraising and lowering a mast 12.

It is a feature of this invention that the truss which connects theupper parts of the front legs of the gin pole includes a top member orchord which extends lengthwise of it and is pivotally supported on ahorizontal axis. Preferably this Vmember is a cylindrical pipe 13 (Figi2),

the opposite ends of which extend into and are journaled in the twosleeves 7. To hold the upper chord in the sleeves at all times, it isprovidedwith collars 14 at the, inner ends of the sleeves and withcircular plates 15 secured to its outer ends and overlapping the outerends of the sleeves. sleeves from moving lengthwise on the upper chordof the truss. .Tournaled onrthe center of this truss member is a sheave16, over which the'fast line 17 (Fig. 3') ex-,

tends from the drawworks 18 to the crown block ,19 of the mast. v

The top chord of the truss is connected by the vusual inclined braces 21to a bottom longitudinal member-.or

chord 22, the opposite ends of which are connected to the front legs 1of the gin pole a short distance below their upper ends. Thispreferably-is done by welding a` longitudinally extending spliceplate/23 to each end of the bottom chord and welding similar plates 24to the inner sides of the front gin pole legs in positions to over.-

lap and engage the front surfaces of the truss splice plates. Theoverlapping pairs of splice plates are pro vided with aligned holes,through which bolts 2S extend for fastening the lower part ot the trusstightly `to the.

legs and then the entire truss can be swung backward, v

due to the novel pivotal mounting of the top of the truss.

When the truss is swung backward in this manner the y splice plates 23at its bottom are jbrought into engage'` ment with the front surfaces ofsplice plates 27 connected to the inner sides of the rear legs 2 in thesame manner as the front splice plates 24. These rear splice plates haveholes 2S aligned with those in the truss splice plates, and the bolts 25are inserted in the holes to tightly connect the bottom of the truss tothe rear legs, as indicated by the inclined broken line position of thetruss in Fig. l. This results in the rear legs being braced by a trusswhile the front legs are free -of the truss.

The advantages of this two position swinging truss are that it can beswung out of the normal line of vision of the drawworks operator whilehe is running the travcling block up and down the mast and watching thederrickman on the racking platform 29 and the gin pole Patented Feb. 5,19574A These collars and plates prevent the` legs which require bracingat any given time can be braced by the truss. Thus, while the mast inFig. 3 is being raised, the front legs 1 of the gin pole are incompression and are braced by the truss attached to them in its forwardposition. At this time the rear gin pole legs 2 are in tension andrequire no lateral support. After the mast has been raised and seatedagainst the gin pole, the rear gin pole legs become compression memberswhich can be braced by the truss in its rear position, because it nolonger is needed between the front legs that cease to take the load. Theuse of the truss to reinforce the back legs of the gin pole permits themto be made of lighter construction than otherwise would be the case.

According to the provisions of the patent statutes, wc have explainedthe principle of our invention and have illustrated and described whatwe now consider to represent its best embodiment. However, we desire tohave it understood that, within the scope of the appended claims, theinvention may be practiced otherwise than as speciically illustrated anddescribed.

We claim:

1. An oil well mast gin pole comprising laterally spaced front legs andlaterally spaced rear legs, means connecting the upper end of each frontleg to the upper end of the leg behind it, each pair of connected legsdiverging downward, a truss between the upper portions of said pairs oflegs and having a top longitudinal member, means pivotally supportingsaid member on a horizontal axis to permit the truss to be swung from aposition between said front legs to a position between said rear legs,means for detachably connecting the opposite ends of the bottom of thetruss to the front legs, and means on the rear legs for connection tothe bottom of the truss when it is swung back to them.

2. An oil well mast gin pole comprising laterally spaced front legs andlaterally spaced rear legs, means connecting the upper end of each frontleg to the upper end of the leg behind it, each pair of connected legsdiverging downward, a truss between the upper portions of said pairs oflegs and having a top longitudinal member connected to them for rotationon its axis to permit the truss to be swung from a position between saidfront legs to a position between said rear legs, the truss having abottom longitudinal member and braces connecting said top and bottommembers, means for detachably connecting the opposite ends of the bottommember of the truss to the front legs, and means on the rear legs forconnection to the bottom member of the truss when it is swung back tothem.

3. An oil well mast gin pole comprising laterally spaced front legs andlaterally spaced rear legs, means connecting the upper end of each frontleg to the upper end of the leg behind it, each pair of connected legsdiverging downward, axially aligned sleeves rigidly mounted on the upperends of said pairs of legs, a truss between the upper portions of saidpairs of legs and having a top longitudinal member journaled in saidsleeves to permit the truss to be swung from a position between saidfront legs to a position between said rear legs, means for detachablyconnecting the opposite ends of the bottom of the truss to the frontlegs, and means on the rear legs for connection to the bottom of thetruss when it is swung back to them.

4. An oil well mast gin pole comprising laterally spaced front legs andlaterally spaced rear legs, means connecting the upper end of each frontleg to the upper end of the leg behind it, each pair of connected legsdiverging downward, axially aligned sleeves rigidly mounted on the upperends of said pairs ot legs, a truss between the upper portions of saidpairs of legs and having a top longitudinal member extending throughsaid sleeves, means mounted on said member at opposite ends of eachsleeve to hold it therein, said member being rotatable in the sleeves topermit the truss to be swung from a position between said front legs toa position between said rear legs, the truss having a bottomlongitudinal member and braces connecting said top and bottom members,means for detachably connecting the opposite ends of the bottom memberof the truss to the front legs, and means on the rear legs forconnection to the bottom member of the truss when it is swung back tothem.

5. An oil well mast gin pole comprising laterally spaced front legs andlaterally spaced rear legs, means connecting the upper end of each frontleg to the upper end of the leg behind it, each pair of connected legsdiverging downward, a truss between the upper portions of said pairsoflegs and having a top longitudinal member, means pivotally supportingsaid member on a horizontal axis to permit the truss to be swung from aposition between said front legs to a position between said rear legs,the bottom of the truss having openings through its opposite ends, saidfront legs having perforated members in front of said openings, andremovable fasteners extending through said perforated members andopenings to detachably connect the bottom of the truss to the frontlegs, said rear legs being provided with perforated members to receiveremovable fasteners extending through said truss openings for detachablyconnecting the bottom of the truss to the rear legs when it is swungback to them.

6. An oil well mast gin pole comprising laterally spaced front legs andlaterally spaced rear legs, means connecting the upper end of each frontleg to the upper end of the leg behind it, each pair of connected legsdiverging downward, a truss between the upper portions of said pairs oflegs and having a top longitudinal member and a bottom longitudinalmember connected by braces, means for detachably connecting the oppositeends of the bottom member to the front: legs, said bottom member andbraces being swingable from the front legs back to the rear legs, andmeans on the rear legs for connection to the opposite ends of saidbottom member when it is swung back to them.

Wengraf June 30, 1935 Athy et al Apr. 25, 1950 *reist

